Structural Protein Function

Structural proteins are a class of proteins that support cell shape and movement. Outside of the cell, these proteins are present in structural body parts, such as bones, cartilage, and skin. 

Collagen, the most abundant protein in mammals, is a structural protein found throughout the body in the extracellular matrix. 

This protein winds into a triple helix that polymerizes into elongated fibrils, which then further assemble into larger fibers. Among its many structural functions, it contributes to cell and tissue shape.

The cytoskeleton is predominantly composed of structural proteins and forms the basic framework of a cell. It contains three main types of filaments: microfilaments, intermediate filaments, and microtubules.

Actin is a structural protein that makes up the microfilaments. This protein self-polymerizes into filaments and contributes to cell shape, organization, movement, and division.

Intermediate filaments can be composed of different proteins depending on the cell type. For example, keratin intermediate filaments are found in epithelial cells, whereas peripherin intermediate filaments are found in the peripheral neurons. The primary structural function of these fil